The early Christian walls of Nicopolis are a well-preserved example of early Byzantine military fortifications.
The walls were constructed after the barbarian invasions in the 3rd to 5th centuries AD and were partly built on existing Roman fortifications.
They cover an area of 180,000 square meters, one-sixth of the Roman city, and feature a masonry technique with horizontal layers of brick and stone zones.
The defensive system was reinforced by numerous towers, including rectangular, circular, and polygonal towers.
The main gate, called the "Arapoporta," is located on the west side and is flanked by two large circular towers.